This invention relates to optical devices and more particularly to a single aperture thermal imager/laser rangefinder.
In the past either separate devices have been used for infrared imaging and laser rangefinding or separate optical channels have been usedxe2x80x94one to transmit laser energy and one to channel the incoming infrared energy and laser energy to a shared array of energy detectors. The latter arrangement was an improvement over the first arrangement in that it permitted common usage of some of the signal detection and processing components which resulted in some space, weight and cost reduction. Nevertheless, these space, weight and cost reduction factors could be maximized with the combining of the optical channels. Those persons skilled in the art considered performance degradation of the infrared imager a serious deterrent to combining the optical channels of these devices.
According, it is an object of this invention to provide a single aperture thermal imager/laser rangefinder.
Another object of the invention is to provide a single aperture thermal imager and laser rangefinder which provides for substantially increased space and weight savings and cost savings.
A further object of the invention is to provide a single aperture thermal imager and laser rangefinder having minimal performance degradation.
Briefly stated the invention comprises the integration of a laser rangefinder with a thermal imager such that they both share the same telescope thereby making the invention a single aperture system. Intergration is made possible through the use of a narrow bandpass beam splitter to separate the laser energy from the thermal imagers bandpass. The performance of the thermal imager is only slightly degraded by splitting out a small section of its bandpass for the laser rangefinder, while the rangefinder""s performance suffer""s no degradation.
Other objects and features of the invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawings, in which: